There are some vehicle headlights in which a discharge lamp provided as a light source and a lighting circuit (ballast) for driving the discharge lamp are arranged in a lighting chamber having a front cover and a lamp body (see, e.g., Japanese Patent Document JP-A-2001-243830).
In the vehicle headlight disclosed in JP-A-2001-243830, a back cover, called a housing engaging portion, is fitted and secured to an opening portion in a rear end portion of a lamp body (lamp housing). A substrate on which a power supply connector and various electronic components are mounted is fitted to the rear surface side of the back cover.
A frame-like wall portion is provided at the rear end portion of the back cover, and cut grooves are formed on the wall portion. The substrate on which the power supply connector and the electronic components are mounted is fitted to the back cover such that the electronic components are arranged on the inner side of the wall portion, and the power supply connector is arranged in a state that such connector is inserted into the cut grooves.
However, in the vehicle headlight disclosed JP-A-2001-243830, the power supply connector such that it is inserted into the cut grooves formed on the rear end portion of the back cover. Therefore, moisture (steam) contained in an outer air or moisture existing on the outer side may enter into the vehicle lighting equipment through a clearance between the power supply connector and the cut grooves.
Moisture entering into the vehicle lighting equipment can negatively impact operation of the lighting circuit of the discharge lamp. Also, the moisture can cause flogging of the front cover in some cases.